This chapter summarizes key properties of porous silicon (pSi) and pSi/polymer composites as a new class of “smart” materials for use in the field of tissue engineering. We begin our discussion with relevant properties of pSi for this application, such as tunable dissolution achieved via facile manipulation of pSi structure thickness, shape and porosity; non-toxic in vivo degradation into orthosilicic acid; along with its strong visible photoluminescence for its use in label-free optical biosensing and self-reporting “smart” drug delivery. Here we present highlights of pSi as a “smart” stimuli-responsive material for the following categories: pH, temperature, and electronic responsiveness; self-reporting biosensing; self-sealing; self-assembling. For each category, a brief description of system fabrication is given, along with the intended use in tissue engineering. This chapter also identifies selected challenges associated with the use of pSi in tissue engineering and how the combination of biodegradable polymers and pSi can be advantageous for selected therapies. We deliberately focus on the use of pSi/polymer composites in ophthalmological tissue engineering and in the field of orthopedics, where for the latter category, a “smart” pSi/polymer system can trigger responsive bone repair. Overall, such stand-alone pSi and pSi/polymer composites present a new class of “smart” materials that can contribute to the constantly evolving field of tissue engineering.